Foods, feeds and cosmetics contain antioxidants (oxidation preventers) as required in order to prevent color Fading or discoloration, a change in the aroma and formation of peroxide during the preservation.
Examples of the antioxidants for the above use include the following.
(1) For foods and feeds
Butylhydroxytoluene (hereinafter referred to as BHT), dl-.alpha.-tocopherol, nordihydroguaiaretic acid, butylhydroxyanisole (hereinafter referred to as BHA) and propyl gallate.
(2) For cosmetics
BHT, dl-.alpha.-tocopherol, BHA and gallic acid.
Being excellent in antioxidant activity and less expensive, BHT is particularly preferentially used as a fat-soluble antioxidant for foods and as a fat-soluble antioxidant for cosmetics.
Meanwhile, with recent eating habits diversified, not only a variety of biological sources are put on the market, but also a variety of processed foods having new ingredients are being developed. With an aesthetical sense uplifted in the field of cosmetics in recent years, a variety of cosmetics having new ingredients are as well being developed.
An immunological study has revealed that the occurrence of human cancer is closely related to a daily life, particularly to eating habits and smoking. In recent years, it has been found that mutagens are developed by heating foods, and that most of these mutagens are nitrogen-containing aromatic heterocyclic compounds having an amino group (heterocyclic amine) (Sugiura T, et al., Perspectives on the Relative Risks, p.31, Mercell Dekker Inc, New York, 1989).
Above all, it has been revealed that 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) formed by heating L-glutamic acid not only exhibits high mutagenic activity to Salmonellae but also exhibits carcinogenic activity to laboratory animals. An experiment with rats has shown that Glu-P-1 has a high rate of incidence of cancer particularly on the liver, large intestine, small intestine and gland of external acoustic meatus (Tkayamz S, et al., Gann, 75, 207, 1984).
It is therefore considered that the risk of carcinogenesis on humans can be avoided or decreased if the mutagenic activity and carcinogenic activity of heterocyclic amine can be inhibited. In particular, the transition of chronic hepatitis and cirrhosis to cancer of the liver is highly liable to occur, and it is a large clinical problem. Not an anti-cancer drug which directly attacks cancer cells, but a compound having a tumor inhibiting activity is considered to work effectively on patients having such diseases.